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Forum: The eyes have it – Alison Brooks takes a close look at some causes of myopia and focuses on modern treatment

By ALISON BROOKS

Optometrists always tell you (or at least they always tell me) that
poor eyesight is not caused by straining the eyes, reading in dim light,
and similar bad practices. Nor, they assure us, does the moderate use of
word processors and television do any harm at all. Eyesight is, they claim
airily, hereditary and tends to get worse as you get older. There’s nothing
you can do about it but get your eyes tested regularly and purchase new
specs as they weaken.

None of this explains the huge numbers of children wearing glasses these
days. Years ago, short-sightedness was rare among children; the occasional
child with spectacles was an object of pity and derision. This was only
twenty or thirty years ago, so I don’t think there can have been hordes
of children suffering from undiagnosed defects of the eye. Today, spectacle-wearers
seem to make up a substantial minority of children. Further, almost all
the young adults I know wear glasses; and my eyesight is worse than my father’s.

It seems that in the 19th century, fewer people wore glasses, as we
can see from photographs. I suggest, from this evidence, that the population
is getting more and more short-sighted. I think we deserve to know why,
as well as what can be done about it. I wonder why optometrists are so reluctant
to tell us. It couldn’t be that they have a massive interest in our having
bad eyesight, could it? It couldn’t be that they put their profits before
our eyesight?

I think we can join the optometrists in dismissing reading in dim light
as the culprit. Electric lighting has all but done away with this. Oh,
I’m sure children still read forbidden matter under the bedclothes with
the aid of a torch, but this is luxury compared with the candles that our
ancestors were forced to use. About the only times these days that we experience
candlelight is in restaurants that don’t wish us to inquire too deeply into
the food. And as we discover, reading even a menu is a major achievement,
if the light is very dim. Yet people actually lived and worked under such
conditions; the Bob Cratchits of that world wrote and added up columns
of numbers by candlelight. No, if people in the 19th century did not suffer
myopia to the extent that we do today, then dim light can hardly be a hazard.

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Among the possible causes of our worsening eyesight, the obvious contenders
are computers and television. Some children spend more time watching TV
at home than they spend at school, and average watching time among children
in Britain is over two hours a day. Many exacerbate the problem by watching
the box from a distance of a few inches, rather than the recommended several
feet. If you can prise computer addicts away from their games, they will
tell you that they spend hours on end zapping and bouncing images across
a screen only inches from their nose. A few optometrists now suggest that
too much of this may well be harmful.

It would be easy to test once and for all whether these factors are
important. Children with normal eyesight could be assigned to four groups.
One group could be encouraged to play with computers; a second, to slump
in front of television for hours on end; a third, to read books; and a fourth,
to go outside and play football or tennis. Although this cannot be a double
blind (ahem) experiment, differences in eyesight which develop later could
be traced with reasonable confidence to their causes, and we would at last
know what causes short-sightedness. This study could even be combined with
an investigation into how these activities affect the children’s long-term
health, intelligence, and level of aggression. An active study of this sort
is preferable to a survey of short-sighted children’s habits; myopic children
will presumably gravitate towards activities like computing, which do not
require good distance vision, so making cause and effect impossible to separate.
Alas, there may be resistance to the idea of experimenting on children in
this way.

Perhaps another look at bad light and eyestrain, from a different angle,
would help. We may actually not be ‘straining’ our eyes enough. After all,
eyestrain is caused by overuse of the eye muscles – exercise, in other words.
Exercise is supposed to be good for the body’s other muscles, so why not
the eyes? Perhaps we don’t exercise our eyes enough. Optometrists decry
theories that exercise can improve eyesight (except in certain restricted
cases, such as double vision), but that doesn’t tell us whether or not exercise
would help prevent deterioration in vision.

The optometrists would perhaps be better advised to follow the medical
profession in concentrating more on preventive medicine, particularly accurate
diagnoses. It might decrease profits from selling spectacles, but only slowly,
over many years. Sales of spectacles to existing customers may decrease
slightly as their eyesight no longer deteriorates regularly, and they no
longer need a new prescription every two years. Fashion could come to the
rescue here, with new designs seducing patients into purchasing new frames
regularly, even though they don’t need them. The main losses would come
in later years from younger people whose eyes do not require the help they
would have otherwise.

The optometrists could recoup this loss by charging for eye exercise
classes. These classes would be outside the domain of the NHS, but I’m sure
that people would be willing to pay if they were convinced that they would
avoid the nuisance of spectacles. On that thought I leave you. I’m off to
my eyerobics class.

Alison Brooks is a palaeontologist who says that her myopia is improving
with age.